Iron and manganese are classified as what type of contaminants?

Iron and manganese are classified as secondary contaminants because they typically affect the aesthetic qualities of drinking water rather than posing a significant health risk. Secondary contaminants are those that can impact the taste, color, or odor of water, leading to potential consumer complaints or dissatisfaction, but are not directly harmful to human health at the concentrations usually found in drinking water.

In terms of compliance, secondary contaminants are subject to guidelines rather than enforceable standards, meaning that while water systems should monitor and manage these substances to maintain water quality, they are not legally required to meet strict health-based standards, unlike primary contaminants. This distinction underscores why iron and manganese are categorized in this manner.